What Is Compaction Grouting?
Compaction grouting is the controlled injection of low-slump, low-mobility, soil/cement grout into the subsurface soils. The intent of the grouting program is to compact loose, coarse-grained soils and displace and/or densify fine-grained soils. How Does Compaction Grouting Work? Because compaction grout is viscous, it does not travel far from the point of injection, even in very loose or weak soils. Rather, a homogeneous grout ‘bulb,’ typically up to 6 feet in diameter, is formed around the injection point, displacing the soil radially. In deeper soils, the bottom-up method is the most common form of compaction grouting. Grout bulb formation commences at the lowest point of the targeted soil zone. Raising of the grout pipe and further grouting cycles at finite intervals results in the continuous formation of a grout bulb ‘column’ through the treatment depth. Overburden depths on the order of 3 – 6 feet are usually required to contain the grout at depth and maximize densification. In s
